European Patent Application No. EP 1 130 227 describes a system for supporting the regeneration of a particle filter situated in an-exhaust duct of a diesel engine, in which the exhaust gas temperature for starting and maintaining the particle filter regeneration is raised by introducing hydrocarbons into the exhaust duct. The exhaust gas temperature is measured in front of an oxidation catalytic converter, behind a diesel particle filter situated next to the catalytic converter as well as between the catalytic converter and the particle filter. The starting point is a specified exhaust gas setpoint temperature to which the diesel particle filter must be brought for initiating the regeneration. The exhaust gas setpoint temperature is essentially raised by a secondary injection of diesel fuel, which results in an increased hydrocarbon content in the exhaust gas, which reacts exothermically in the oxidation catalytic converter. The secondary injections are maintained at least until the specified exhaust gas setpoint temperature is measured.
German Patent Application No. DE 44 26 020 describes a method for monitoring the functionality of a catalytic converter situated in an exhaust duct of an internal combustion engine, which begins from two temperature signals. The first temperature signal is measured downstream of the catalytic converter. The second temperature signal is ascertained using a model that reflects a temperature rise by an exothermic reaction of hydrocarbons in the catalytic converter. Subsequently, the two temperature signals are adjusted in a specified operating state of the internal combustion engine. In the subsequent operation of the internal combustion engine, the catalytic converter is diagnosed by comparing the two temperature signals.
The present invention is based on an objective of providing a method for metering a fuel into an exhaust duct of an internal combustion engine and a device for implementing the method, which allow for metering that is as exact as possible.